Study Published in Child and Adolescent Psychiatry and Mental Health Demonstrated Once-Daily Vyvanse® (lisdexamfetamine dimesylate) CII Provided Significant Improvement of ADHD Symptoms for Children at 13 Hours After Administration

Vyvanse is the first oral ADHD stimulant with published data
that demonstrated significant ADHD symptom improvement from 1.5
hours up to 13 hours after administration in children, from morning
through homework and family time

PHILADEPHIA – July 22, 2009 – Shire plc (LSE: SHP,
NASDAQ: SHPGY), the global specialty biopharmaceutical company,
today announced that a study published online in the peer-reviewed
journal Child and Adolescent Psychiatry and Mental Health
found once-daily Vyvanse® (lisdexamfetamine dimesylate) CII
significantly reduced the symptoms of
Attention-Deficit/Hyperactivity Disorder (ADHD) in children aged 6
to 12 from the first time point measured (1.5 hours) up to the last
time point assessed (13 hours) after administration. In this
pediatric analog classroom study, treatment with Vyvanse was
associated with significant improvement in behavior and attention
in children at each time point measured, with improvement at 13
hours after administration.

“Pediatric patients may require ADHD symptom improvement
both at school and after school,” said Sharon Wigal, PhD,
lead investigator of the study, clinical professor of pediatrics
and director of clinical trials in the Child Development Center at
the University of California, Irvine. “These published
data are the first to have shown duration of effect of an oral ADHD
stimulant in children aged 6 to 12 at 13 hours after
administration. Physicians and caregivers who are seeking a
long-acting medication that provides ADHD symptom improvement from
morning through homework and family time may want to consider this
Vyvanse study data.”

On May 22, 2009, the US Food and Drug Administration (FDA)
approved a change to the prescribing information for Vyvanse to
include supplemental data that demonstrated significant ADHD
symptom improvement in children aged 6 to 12 from the first time
point measured (1.5 hours) up to 13 hours postdose. Vyvanse
is now the first and only oral ADHD stimulant treatment to have
efficacy at 13 hours after administration for pediatric patients
included in its product labeling.

“Shire is proud to be at the forefront of ADHD research
and treatment development and is committed to providing patients
with effective ADHD medications, such as Vyvanse,” said Liza
Squires, MD, Research and Development Business Unit Leader for
Shire. “These findings provided further support that
Vyvanse can be an important treatment option for children who
require duration of ADHD symptom improvement throughout the
day.”

The study was a randomized, double-blind, placebo-controlled,
analog classroom study that assessed the efficacy and safety of
Vyvanse in 129 children aged 6 to 12 years with ADHD.
Following a four-week, open-label, dose-optimization phase with
Vyvanse at 30 mg, 50 mg, and 70 mg doses, patients entered a
two-week, double-blind, crossover phase where they were randomized
into two groups. One group received their optimal dose of
Vyvanse the first week and placebo the second week. The
second group received placebo the first week and their optimal dose
of Vyvanse the second week.

The primary objective of this study was to assess the time of
onset of Vyvanse compared with placebo, as measured by the Swanson,
Kotkin, Agler, M-Flynn, and Pelham Deportment

(SKAMP-D) rating scale. Secondary objectives included
assessment of the duration of efficacy of VYVANSE compared with
placebo, as measured by the SKAMP-D scale, and assessment of
efficacy and time of onset of Vyvanse compared with placebo as
measured by SKAMP Attention (SKAMP-A), and Permanent Product
Measure of Performance (PERMP) scales.

In the study, Vyvanse demonstrated significant efficacy versus
placebo at 1.5 hours, the first time point measured. Further,
Vyvanse treatment was associated with significant efficacy as
measured by both subjective (SKAMP-D and SKAMP-A) and objective
(PERMP) assessments from the first time point (1.5 hours) through
the last time point (13 hours) assessed during the classroom day,
and at all time points in between (2.5, 5.0, 7.5, 10.0, and 12.0
hours).

Safety was also evaluated during the study. The adverse
event profile for Vyvanse was similar to other currently marketed
stimulants. The most frequently reported adverse events
(greater than or equal to 10 percent) in the dose-optimization
phase for patients taking Vyvanse were decreased appetite,
insomnia, headache, irritability, upper abdominal pain, and affect
lability.

Vyvanse, which was introduced in the United States in July 2007
for the treatment of ADHD in children aged 6 to 12 years and
approved in April 2008 to treat ADHD in adults, is currently
available in six dosage strengths of 20 mg, 30 mg, 40 mg, 50 mg, 60
mg, and 70 mg. To date, more than 6 million Vyvanse
prescriptions have been filled, bringing the current US market
share to over 12 percent based on weekly branded prescription
volume. Additionally, Shire has executed agreements with 10
of Shire’s top 11 managed care organizations (MCOs) to cover
Vyvanse in a preferred formulary position.

Vyvanse is a therapeutically inactive prodrug, in which
d-amphetamine is covalently bonded to

l-lysine, and after oral ingestion it is converted to
pharmacologically active d-amphetamine. The conversion of
Vyvanse to d-amphetamine is not affected by gastrointestinal pH and
is unlikely to be affected by alterations in GI transit times.

Additional information about Vyvanse and Full Prescribing
Information, including Medication Guide, are available at
www.vyvanse.com.

The Permanent Product Measure of Performance (PERMP) is an
age-adjusted collection of math problems that provides an objective
measure of performance based on the number of attempted and
completed math problems.

About VYVANSE

Vyvanse is indicated for the treatment of ADHD. Efficacy
based on two controlled trials in children aged 6 to 12 and one
controlled trial in adults.

Tell the doctor about any heart conditions, including structural
abnormalities, that you, your child, or a family member, may
have. Inform the doctor immediately if you or your
child develops symptoms that suggest heart problems, such as chest
pain or fainting.

Vyvanse should not be taken if you or your child has advanced
disease of the blood vessels (arteriosclerosis); symptomatic heart
disease; moderate to severe high blood pressure; overactive thyroid
gland (hyperthyroidism); known allergy or unusual reactions to
drugs called sympathomimetic amines (for example, pseudoephedrine);
seizures; glaucoma; a history of problems with alcohol or drugs;
agitated states; taken a monoamine oxidase inhibitor (MAOI) within
the last 14 days.

Tell the doctor before taking Vyvanse if you or your child is
being treated for or has symptoms of depression (sadness,
worthlessness, or hopelessness) or bipolar disorder; has abnormal
thought or visions, hears abnormal sounds, or has been diagnosed
with psychosis; has had seizures or abnormal EEGs; has or has had
high blood pressure; exhibits aggressive behavior or
hostility. Tell the doctor immediately if you or your child
develops any of these conditions or symptoms while taking
Vyvanse.

Abuse of amphetamines may lead to dependence. Misuse of
amphetamine may cause sudden death and serious cardiovascular
adverse events. These events have also been reported rarely
with amphetamine use.

Talk to your health care provider if your child experiences
slowing of growth (height and weight). Children should have
their height and weight checked periodically while taking
Vyvanse. Your health care provider may stop Vyvanse treatment
if a problem is found during these check-ups.

Vyvanse was generally well tolerated in clinical studies. The
most common side effects reported in studies of Vyvanse were:
children – decreased appetite, difficulty falling asleep,
stomachache, and irritability; adult – decreased appetite,
difficulty falling asleep, and dry mouth.

Aggression, new abnormal thoughts/behaviors, mania, growth
suppression, worsening of motion or verbal tics, and
Tourette’s syndrome have been associated with use of drugs of
this type. Tell the doctor if you or your child has blurred
vision while taking Vyvanse.

About ADHD

ADHD is one of the most common psychiatric disorders in children
and adolescents. Worldwide prevalence of ADHD is estimated at
5.3 percent (with large variability), according to a comprehensive
systematic review of this topic published in 2007 in the American
Journal of Psychiatry. In the United States, approximately
7.8 percent of all school-aged children, or about 4.4 million
children aged 4 to 17 years, have been diagnosed with ADHD at some
point in their lives, according to the Centers for Disease Control
and Prevention (CDC). The disorder is also estimated to
affect 4.4 percent of US adults aged 18 to 44 based on results from
the National Comorbidity Survey Replication. When this
percentage is extrapolated to the full US population aged 18 and
over, approximately 9.8 million adults are believed to have
ADHD.

ADHD is a psychiatric behavioral disorder that manifests as a
persistent pattern of inattention and/or hyperactivity-impulsivity
that is more frequent and severe than is typically observed in
individuals at a comparable level of development. The
specific etiology of ADHD is unknown and there is no single
diagnostic test for this syndrome. Adequate diagnosis
requires the use of medical and special psychological, educational
and social resources, utilizing diagnostic criteria such as
Diagnostic and Statistical Manual of Mental Disorders-IV
(DSM-IV-TR) or International Classification of Diseases 10
(ICD-10).

Although there is no “cure” for ADHD, there are
accepted treatments that specifically target its symptoms. Standard
treatments include educational approaches, psychological, or
behavioral modification, and medication.

SHIRE PLC
Shire’s strategic goal is to become the leading specialty
biopharmaceutical company that focuses on meeting the needs of the
specialist physician. Shire focuses its business on attention
deficit and hyperactivity disorder (ADHD), human genetic therapies
(HGT) and gastrointestinal (GI) diseases as well as opportunities
in other therapeutic areas to the extent they arise through
acquisitions. Shire’s in-licensing, merger and acquisition
efforts are focused on products in specialist markets with strong
intellectual property protection and global rights. Shire believes
that a carefully selected and balanced portfolio of products with
strategically aligned and relatively small-scale sales forces will
deliver strong results.

For further information on Shire, please visit the
Company’s Web site: www.shire.com.

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forward-looking statements. Such forward-looking statements involve
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Company’s results could be materially adversely affected. The
risks and uncertainties include, but are not limited to, risks
associated with: the inherent uncertainty of research, development,
approval, reimbursement, manufacturing and commercialization of the
Company’s Specialty Pharmaceutical and Human Genetic
Therapies products, as well as the ability to secure and integrate
new products for commercialization and/or development; government
regulation of the Company’s products; the Company’s
ability to manufacture its products in sufficient quantities to
meet demand; the impact of competitive therapies on the
Company’s products; the Company’s ability to register,
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